#viewer {
    padding: 40px 0px;
    column-count: 3;
}
#viewer li {
    position: relative;
    list-style: none;
    float: left;
    padding: 10px 2px;
}
#viewer li img {
    width: 350px;
}
#viewer li .edge {
    position: absolute;
    width: 350px;
    background-color: #000;
    text-align: center;
    bottom: 10px;
    font-size: 16px;
    opacity: 0;
    color: #fff;
    transition: opacity 1s ease-in;
}
#viewer li:hover .edge{
    opacity: .5;
    transition: .5s ease-in;
}
